How many solar systems are there in the milky way?
The galactic center is an intense radio source known as Sagittarius A*, a supermassive black hole of 4,100 (± 0.03 million solar masses. This illustration shows what the surface of TRAPPIST-1f, one of the seven planets in the TRAPPIST-1 system, might look like. The apex of the Sun’s path, or solar apex, is the direction … Read more